<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
window.onload = function() {
	
	var oDiv = document.getElementById('div1');
	
	/*
		width height
		style.width : 样式宽
		clientWidth : 可视区宽
		offsetWidth	: 占位宽
	*/
	
	alert( oDiv.style.width );	//100
	alert( oDiv.clientWidth );	//样式宽 + padding	120
	alert( oDiv.offsetWidth );	//样式宽 + padding + border  可视区宽 + 边框	122
	
}
</script>
</head>

<body>
	<div id="div1" style="width: 100px; height: 100px; border: 1px solid red; padding: 10px; margin: 10px;"></div>
</body>
</html>
